"This is called "the Living Room,'" Bob Gregson told the kids waiting outside the door to his new exhibit, "but it's a little bit different from your living room at home. There's no color tevelsions, for one thing. And in your living room at home, you probably don't rearrange the furniture when your mother's out. But in this room you can make things happen."

His visitors, 16 third-graders from Wolf Trap Elementary School in Vienna, looked doubtful, but filed dutifully into the room. Except for a few big storage bins it was empty. "Let's see how many different ways we can change the room," Gregson began, after they'd all plunked down on the gray carpet. "What would be neat would be if we could make a big building. . ."

He never got a chance to finish his sentence. Sixteen eight-year-olds tearing through storage bins drowned him out. They discovered huge trapezoidal cardboard building blocks, which they turned into footballs, tools, chairs and tables. They draped hollow plastic tubing through ceiling pipes, making telephones and pulleys. They dragged each other aroung in fish nets, pulled pieces of foam rubber, draped parachute material, tried on wigs, swung from pipes and locked one another up in cabinets.

In 30 seconds flat, they turned "The Living Room" into "The Zoo."

The living room is a place where "nothing happens unless there are people in it," according to Gregson, who dreamed it up. "It's a room for transformations -- the ceiling can be raised or lowered, lights go on and off, boxes can be rolled around. There's no room like this anywhere in the world. I'm very proud of this place."

Gregson's creation is one of three major exhibits at the Capital Children's Museum, which recently set up shop in an old convent on Capital Hill. Its purported purpose is to encurage cooperation and creativity. The kids who tear the room apart would probably just call it having fun.

"Heave! Ho! shouted Eddie, nine, as he swung from a long piece of foam rubber he'd drapped through the ceiling. He ran over to inspect the jungle gym, which kids had draped with a parachute, and was later found stacking huge cardboard blocks. What was he buliding? "I don't know. What is it, Andy?" Eddie asked. Andy thought for a minute, then brightened. "it's the Empire Block Building!"

From the middle of it all came Gregson's voice: "Maybe we can start builing a wall over here. . ."

"it's the best room I've ever been in'"said Julie, Eight, as she jumped from a shiny red box. "It's neat! there's lost s of stuff to play with "

Melissa, also eight, shook her head. "i think it's a disaster. All these things re hanging everhwhere. . . Will we have to clean it up?" Yes, said program assitant Vicky Noonan, who was standing nearby. "But how? It'll take us 29 hours!" Melissa wailed. "The same way we took it apart," said Noonan. She picked up one end of a long rubber tube and continued their conversation by telephone. You couldn't hear her, but Melissa's voice came through loud and clear: "Melissa! [pause] 8 1/2! [pause] February 1st! [pause] It's a disaster!"

"I think the living room's weird," announced Colleen, eight, to nobody in particular.

"It isn't anything like I expected," said Sally Etherington, one of the mothers, whose son Darin, "pushing nine," was parachuting off the jungle gym. "It's interesting the way they started out not knowing what to do, and now some are coming up with furniture, some are building walls. That little boy in the brown has worked and worked on that wall, and inevitably someone will knock it down, and he gets mad."

After they'd cleaned everything up -- it took less than a minute -- the kids sat on the floor and thought it all over. "Does it look like you did anything?" Gregson asked rhetorically. "It's all gone, isn't it?"

They talked about what they had made. "We built a fort," called out two little boys. "Kelly made a seat-belt thing." "I made an intercom system." "I played with the lights."

I made a mess," said one little girl succinctly.

When they had gone, Gregson and Noonan collasped on the floor."They always amaze me," Gregson said. "The things they find, the way they play -- they always find a new solution. It seems chaotic, but if you looked around at the smaller moments, there were people doing things. It wasn't just wild."

Maybe they'd divide the kids into smaller groups next time, they decided, and let everyone show off what they built before they cleaned up. "Hey, yeah," said Gregson, perking up. "We could have a little festival, like a parade through a little city . . ."

There was a clomping noise on the stairs. Another group was waiting to come in.